A series of sulfonated polyimides （SPIs） containing pyridine groups were prepared by direct polycondensation from 1,4,5,8-naphthalenetetracarboxylic dianhydride （NTDA）, 4,4＇-diaminodiphenyl ether-2,2＇-disulfonic...A series of sulfonated polyimides （SPIs） containing pyridine groups were prepared by direct polycondensation from 1,4,5,8-naphthalenetetracarboxylic dianhydride （NTDA）, 4,4＇-diaminodiphenyl ether-2,2＇-disulfonic acid （ODADS） and 4-（4-methoxy）phenyl-2,6-bis（4-aminophenyl）pyridine （DAM）. The resulting copolymers displayed good solubility in common organic solvents. Flexible, transparent, tough membranes were obtained via solution casting. All the films showed high thermal stability with desulfonation temperature over 300℃. They exhibited prominent mechanical properties with Young＇s modulus around 2.0 GPa. High proton conductivity （0.23 S/cm at 100% RH） was also observed. More importantly, the new materials exhibited low water uptake （30 wt%-75 wt% at 80℃） and improved water stability, which were attributed to the acid-base interaction between sulfonic acid and pyridine functional groups.展开更多
A series of sulfonated polyimide copolymers as novel proton exchange materials were synthesized by the polycondensation of 1,4,5,8-naphthalene-tetracarboxylic dianhydride （NTDA）, sulfonated diamine based on pyridine...A series of sulfonated polyimide copolymers as novel proton exchange materials were synthesized by the polycondensation of 1,4,5,8-naphthalene-tetracarboxylic dianhydride （NTDA）, sulfonated diamine based on pyridine group and diamine containing N-phenyl-1,2,4-triazole moiety. Flexible, transparent and tough membranes with high thermal stability and good mechanical properties were obtained. They exhibited good stability in boiling water and Fenton＇s reagent at 80 ℃. More interestingly, a nonlinear relationship between proton conductivities of the resulting membranes and the degree of sulfonation （DS） was observed. The membrane with 50% DS exhibited the maximum proton conductivity, which was due to the combinational contributions of sulfonic acid and N-pheny-1,2,4-triazole groups. Thus, the N-phenyl-l,2,4- triazole moiety in this study not only can depress water absorption but also increase proton conductivity, especially at low DS.展开更多
A novel sulfonated diamine monomer, 1,2-dihydro-2-(3-sulfonic-4-aminophenyl)-4-[4-(4-aminophenoxy)-phenyl]phthalazin-1-one (S-DHPZDA), was successfully synthesized by direct sulfonation of diamine 1,2-dihydro-2-(4-ami...A novel sulfonated diamine monomer, 1,2-dihydro-2-(3-sulfonic-4-aminophenyl)-4-[4-(4-aminophenoxy)-phenyl]phthalazin-1-one (S-DHPZDA), was successfully synthesized by direct sulfonation of diamine 1,2-dihydro-2-(4-aminophenyl)-4-[4-(4-aminophenoxy)-phenyl]-phthalazin-1-one (DHPZDA). A series of sulfonated polyimides (SPIs), which can be used as the material of the proton exchange membrane (PEM) for the proton exchange membrane fuel cell (PEMFC), were prepared from 1,4,5,8-naphthalenetetracarboxylic dianhydride (NTDA), S-DHPZDA, and nonsulfonated diamines DHPZDA. The structure of the monomer and polymers were characterized by FT-IR and 1H NMR. The solubility of the S-DHPZDA-based SPIs has been improved due to the induction of the phthalazione moiety. The SPIs membranes have high thermo-stability, predominant swelling resistance with high ion exchange capacity.展开更多
The novel sulfonated polyimide membranes were successfully synthesized by thermal imidization with monomers of 4,4＇-（hexafluoroisopropylidene）diphthalic anhydride （6FDA）, 4,4＇-diamino- diphenyl ether-2,2＇-disul...The novel sulfonated polyimide membranes were successfully synthesized by thermal imidization with monomers of 4,4＇-（hexafluoroisopropylidene）diphthalic anhydride （6FDA）, 4,4＇-diamino- diphenyl ether-2,2＇-disulfonic acid （SODA） and 3,3 ＇-diaminochalcone （3DAC）. Photosensitive chalcone moiety was introduced to the main chain of copolymers, and the photocrosslinking of resulting copolymer in aqueous electrolyte was attempted. A series of sulfonated copolyimide precursors containing chalcone functional groups in the main chain were prepared with different sulfonation degrees by controlling the molar ratio of SODA, 6FDA and 3DAC. The polymer membranes were prepared from these sulfonated aromatic precursors by solution casting and subsequent thermal imidization. The crosslinking with UV irradiation was attempted in the presence or absence of distilled water. The characterizations of the resulting membrane such as the ion-exchange capacity, water absorption and ionic conductivity were performed with respect to the copolymer compositions and the photocrosslinking conditions.展开更多
基金financially supported by the Department of Science and Technology of Jilin Province(No.20086019)the 863 Project from the Ministry of Science and Technology of China(No.2006AA03Z224)
文摘A series of sulfonated polyimides （SPIs） containing pyridine groups were prepared by direct polycondensation from 1,4,5,8-naphthalenetetracarboxylic dianhydride （NTDA）, 4,4＇-diaminodiphenyl ether-2,2＇-disulfonic acid （ODADS） and 4-（4-methoxy）phenyl-2,6-bis（4-aminophenyl）pyridine （DAM）. The resulting copolymers displayed good solubility in common organic solvents. Flexible, transparent, tough membranes were obtained via solution casting. All the films showed high thermal stability with desulfonation temperature over 300℃. They exhibited prominent mechanical properties with Young＇s modulus around 2.0 GPa. High proton conductivity （0.23 S/cm at 100% RH） was also observed. More importantly, the new materials exhibited low water uptake （30 wt%-75 wt% at 80℃） and improved water stability, which were attributed to the acid-base interaction between sulfonic acid and pyridine functional groups.
文摘A series of sulfonated polyimide copolymers as novel proton exchange materials were synthesized by the polycondensation of 1,4,5,8-naphthalene-tetracarboxylic dianhydride （NTDA）, sulfonated diamine based on pyridine group and diamine containing N-phenyl-1,2,4-triazole moiety. Flexible, transparent and tough membranes with high thermal stability and good mechanical properties were obtained. They exhibited good stability in boiling water and Fenton＇s reagent at 80 ℃. More interestingly, a nonlinear relationship between proton conductivities of the resulting membranes and the degree of sulfonation （DS） was observed. The membrane with 50% DS exhibited the maximum proton conductivity, which was due to the combinational contributions of sulfonic acid and N-pheny-1,2,4-triazole groups. Thus, the N-phenyl-l,2,4- triazole moiety in this study not only can depress water absorption but also increase proton conductivity, especially at low DS.
文摘A novel sulfonated diamine monomer, 1,2-dihydro-2-(3-sulfonic-4-aminophenyl)-4-[4-(4-aminophenoxy)-phenyl]phthalazin-1-one (S-DHPZDA), was successfully synthesized by direct sulfonation of diamine 1,2-dihydro-2-(4-aminophenyl)-4-[4-(4-aminophenoxy)-phenyl]-phthalazin-1-one (DHPZDA). A series of sulfonated polyimides (SPIs), which can be used as the material of the proton exchange membrane (PEM) for the proton exchange membrane fuel cell (PEMFC), were prepared from 1,4,5,8-naphthalenetetracarboxylic dianhydride (NTDA), S-DHPZDA, and nonsulfonated diamines DHPZDA. The structure of the monomer and polymers were characterized by FT-IR and 1H NMR. The solubility of the S-DHPZDA-based SPIs has been improved due to the induction of the phthalazione moiety. The SPIs membranes have high thermo-stability, predominant swelling resistance with high ion exchange capacity.
基金Funded by the New & Renewable Energy R&D Program(2009T100100606) under the Ministry of Knowledge Economy of Koreathe National Research Foundation of Korea (NRF) through the Human Resource Training Project for Regional Innovation
文摘The novel sulfonated polyimide membranes were successfully synthesized by thermal imidization with monomers of 4,4＇-（hexafluoroisopropylidene）diphthalic anhydride （6FDA）, 4,4＇-diamino- diphenyl ether-2,2＇-disulfonic acid （SODA） and 3,3 ＇-diaminochalcone （3DAC）. Photosensitive chalcone moiety was introduced to the main chain of copolymers, and the photocrosslinking of resulting copolymer in aqueous electrolyte was attempted. A series of sulfonated copolyimide precursors containing chalcone functional groups in the main chain were prepared with different sulfonation degrees by controlling the molar ratio of SODA, 6FDA and 3DAC. The polymer membranes were prepared from these sulfonated aromatic precursors by solution casting and subsequent thermal imidization. The crosslinking with UV irradiation was attempted in the presence or absence of distilled water. The characterizations of the resulting membrane such as the ion-exchange capacity, water absorption and ionic conductivity were performed with respect to the copolymer compositions and the photocrosslinking conditions.
